A Relational Database Machine for Very Large Information Retrieval Systems

An overview is presented of a new advanced relational database machine (ADAM) for very large information retrieval systems. Novel features of ADAM are as follows. (1) A relation is divided into several parts and stored in general purpose magnetic disks. A parallel access method and a clustering technique based on the extended K-d tree are employed to shorten data transfer time from disks to the main memory. (2) Selection operations are performed at the time of the data transfer by specialized hardware attached to a disk controller. A table based on the finite state machine is used to perform text search of selection operations. (3) The three-phase (filtering, sorting and comparing) join method is used to accelerate join operations. Each phase is performed in parallel by specialized hardware.